title: A hospital-based cross-sectional study to develop an estimation formula for 2-h post-challenge plasma glucose for screening impaired glucose tolerance.
abstract: OBJECTIVE
  To create and validate an estimation formula for 2-h post-challenge plasma glucose (2-hPG) as an alternative to oral glucose tolerance test (OGTT) for impaired glucose tolerance (IGT) screening.
  
  
  METHODS
  380 Japanese subjects (57.6% males, aged 58.5 (14.0); mean (SD) years) undergoing OGTT were included in this hospital-based cross-sectional study mainly at Kyoto University Hospital between 2000 and 2011. We determined the main predictive variables of 2-hPG from clinical variables and separated the subjects randomly into two groups: a derivation group to construct an estimation formula of 2-hPG on the basis of predictive variables and a validation group to evaluate the accuracy of the formula.
  
  
  RESULTS
  Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) were highly correlated with 2-hPG measured by OGTT. Multiple linear regression analysis showed that estimated 2-hPG (e2-hPG) was calculated by the formula: e2-hPG = 1.66 × FPG (mmol/l) + 1.63 × HbA1c (%)-10.11 (R(2), coefficient of determination=60.2%). When the cut-off value was set to the diagnostic criteria of IGT, 7.8 mmol/l of e2-hPG, sensitivity, specificity, and negative predictive value (NPV) were 83.3%, 44.1%, and 74.3%, respectively. When the cut-off value was set lower (7.2 mmol/l), these values were 94.4%, 30.5%, and 85.7%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.68.
  
  
  CONCLUSIONS
  This high-sensitive estimation formula may be a useful alternative to OGTT for IGT screening. For the levels ≤ 7.2 mmol/l, this formula may also be useful in cross-sectional study to identify people whose glucose tolerance is normal.
authors.affiliation: Department of Diabetes and Clinical Nutrition, Graduate School of Medicine, Kyoto University, Japan.
authors.forename: Yaeko
authors.initials: Y
authors.lastname: Kondo
authors.forename: Norio
authors.initials: N
authors.lastname: Harada
authors.forename: Takashi
authors.initials: T
authors.lastname: Sozu
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hamasaki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yamane
authors.forename: Atsushi
authors.initials: A
authors.lastname: Muraoka
authors.forename: Takanari
authors.initials: T
authors.lastname: Harada
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Shibue
authors.forename: Daniela
authors.initials: D
authors.lastname: Nasteska
authors.forename: Erina
authors.initials: E
authors.lastname: Joo
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sasaki
authors.forename: Nobuya
authors.initials: N
authors.lastname: Inagaki
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D003430:Cross-Sectional Studies; D005215:Fasting / Q000097:blood; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000175:diagnosis*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: IGT; OGTT; Screening